A conventional line-type inkjet recording apparatus includes a plurality of conveying roller pairs for conveying a recording medium in a conveying direction, and a plurality of recording heads for ejecting inks of different colors. In the line-type inkjet recording apparatus, the plurality of recording heads is arranged in the conveying direction at predetermined intervals. In this type of line-type inkjet recording apparatus, recording positions in a recording medium for the recording heads may be shifted when a conveyance amount per unit time of the recording medium varies due to a change in a surface of a conveying roller.
The conventional inkjet recording apparatus obtains, for each of the plurality of recording heads, a deviation amount (an offset) of a recording position in the recording medium with respect to a recording position of the reference recording head and adds non-image data to respective recording data of the plurality of recording heads on the basis of the respective deviation amounts, to correct the deviation in the recording medium between the recording positions of the recording heads.